Project description:The purpose of this study was to examine how Mtb integrates acidic pH and available carbon sources as environmental cues to regulate its metabolism and growth rate. RNA-seq transcriptional profiling of M. tuberculosis growing at acidic or neutral pH, in pyruvate or glycerol, was examined. These studies identified carbon source-dependent and -independent pH-dependent adaptations.
Project description:The purpose of this study was to examine how Mtb integrates acidic pH and available carbon sources as environmental cues to regulate its metabolism and growth rate. RNA-seq transcriptional profiling of M. tuberculosis growing at acidic or neutral pH, in pyruvate or glycerol, was examined. These studies identified carbon source-dependent and -independent pH-dependent adaptations. Mtb strain CDC1551 was grown in standing T-75 flasks in 40 mL of medium seeded an initial OD of 0.1. We examined medium in four conditions pH 7.0 10 mM glycerol, pH 5.7 10 mM glycerol, pH 7.0 10 mM pyruvate, pH 5.7 10 mM pyruvate. Following 3 days of incubation at 37C, RNA was isolated from the bacterial cultures and used for RNA-seq.
Project description:We analyzed the genes expressed, or the transcriptome, of bacilli (Mycobacterium tuberculosis) growing in fatty acids as sole carbon source. Using new technologies to massively sequence of RNA molecules we identified a group of genes that provides novel insight regarding the metabolic pathways and transcriptional regulation of latent M. Tuberculosis.
Project description:We analyzed the genes expressed, or the transcriptome, of bacilli (Mycobacterium tuberculosis) growing in fatty acids as sole carbon source. Using new technologies to massively sequence of RNA molecules we identified a group of genes that provides novel insight regarding the metabolic pathways and transcriptional regulation of latent M. Tuberculosis. Comparative Transcriptomics between two carbon source (Dextrose, Long Fatty Acids), at two states of growth (Exponential and Stationary Phase)
Project description:The success of Mycobacterium tuberculosis (Mtb) is largely due to its ability to withstand numerous stresses imposed by host immunity. Here, we present a data-driven model that captures these adaptive mechanisms and reveals the dynamic interplay of host-derived stresses and genome-encoded regulatory programs in Mtb. The model captures the genome-wide distribution of cis-acting gene regulatory elements and the conditional influences of transcription factors at those elements to elicit environment-specific responses. Analysis of transcriptional responses that may be essential for Mtb’s survival in acidic conditions identified regulatory control by the MtrAB two-component signal system. This data is a comparison of transcriptional differences (RNA-seq) between low pH (pH 5.6) and neutral pH (pH7) of Mtb
Project description:The purpose of this study was to determine (i) the interplay between Mycobacterium tuberculosis response to acidic pH and cholesterol, two signals experienced concurrently by the bacterium during host colonization, and (ii) the role of the transcription factor Mce3R in regulation of this response.
Project description:Following phagocytosis by macrophages, Mycobacterium tuberculosis (Mtb) senses the intracellular environment and remodels its gene expression for growth in the phagosome. Abramovitch et.al. in this current study identified an Acid and Phagosome Regulated (aprABC) locus that is unique to the Mtb complex and whose gene expression is induced during growth in acidic environments in vitro and in macrophages. The authors propose a model where phoP senses the acidic pH of the phagosome and induces aprABC expression to fine-tune processes unique for intracellular adaptation of Mtb complex bacteria. This study uses microarray analyses to compare transcriptional responses of wild type Mycobacterium tuberculosis (CDC1551) to aprABC locus deletion mutants and the phoP transposon mutant. The bacteria were grown to early log phase in vented T-75 standing flasks containing 12 mL of pH 7.0 7H9 OADC medium. Transcript levels of the wild type bacteria were compared to the following mutants: aprABC null, aprBC null, aprC null, phoP::Tn mutant.
Project description:We present the data obtained from high-resolution ribosome profiling analysis of Mycobacterium tuberculosis grown under standard conditions (log phase) and cells subjected to oxidative stress (50 µM cumene hydroperoxide) and pH stress (pH 4.5). Our data shows pervasive ribosome pausing in the M. tb translatome. A large number of genes show very high pause immediately downstream to the translation start site. Moreover, serines and alanines in the E site of the ribosome exhibit highest pause scores.
Project description:The purpose of this study was to understand how prevention of serine/threonine protein kinase (STPK) phosphorylation of PrrA impacts PrrA modulation of M. tuberculosis transcriptional response to acidic pH and high chloride levels.
Project description:The stringent response, involving the regulatory molecules inorganic polyphosphate (poly P) and (p)ppGpp, is believed to mediate Mycobacterium tuberculosis persistence. In this study, we identified a novel exopolyphosphatase responsible for poly P hydrolysis. Using two different poly P-accumulating M. tuberculosis recombinant strains, we found that increased poly P content drives the organisms into early growth arrest, and contributes to tolerance to the cell wall-active agent isoniazid, increased resistance to stress conditions, and improved survival in macrophages. Transcriptomic and metabolomics analysis revealed metabolic downshift manifested by reduced expression of the transcriptional and translational machinery, and shift from utilization of glucose as a carbon source. In summary, regulation of the poly P balance is critical for persister formation in M. tuberculosis.
